theweatheroutlook

Remove ads from site

John Mason
12 January 2011 16:19:41



Happy new year, all!


"As for loss of Artic Ice - fits in well with a meridional jet - as has been explained on many occasions, a meridional jet pattern warms Polar regions, even as it cools the hemisphere in general."


We have had meridional patterns many times before though. How does that fit in with the general trend of less and less sea-ice through time?


I would suggest very anomalously low-ice years are a combined result of hyper-meridionality AND GHG-related warming. Given that, in turn, less ice may encourage more meridionality, we also appear to have an identifiable example of a positive feedback effect at work.


Cheers - John


Originally Posted by: Maunder Minimum 


I find it hard to understand how GHG related warming could be responsible for loss of Artic sea ice at this juncture - it is simply too early for such an effect to become apparent. There must be other explanations for low sea ice. We had a 30 year spell of positive PDO and regular El Ninos to deal with and therein lies some of the reason for the current situation. I expect the loss of sea ice to reverse in coming years as a consequence of the PDO going negative and other natural cyclic changes in the global climate. It is facile to put current low levels of Artic sea ice down to GHG - during the MWP, there is evidence that Artic conditions were far more benign than subsequently - when the Vikings called Greenland by its name in the 10th century, it wasn't simply for a joke.


Originally Posted by: John Mason 


 


Why too early?


CO2 concentrations have been higher than in the Interglacial maxes for decades!


Cheers - John

Gray-Wolf
13 January 2011 10:16:32

Though the AGW adherents are accused of ignoring 'natural cycles' when looking at climate change it seems that the 'skeptiks' are as guilty when looking at the Arctic situation?


It is not the existence of 'natural cycles' that has made the difference here but the 'extra' that AGW brought to the table over two 'melt periods' across the 20th century.


Without this 'extra' we would just be in the 'normal' Arctic variance ' and not with no perennial ice left and closing in on a 'seasonal pack'.


We have to accept that some systems are 'finely balanced' and that over a century of 'added melt' will eventually bring us to the point where systems which once 'helped' maintain the Arctic now actively destroy the ice there.

Koyaanisqatsi
ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
VIRESCIT VULNERE VIRTUS
polarwind
13 January 2011 14:10:08



Happy new year, all!


"As for loss of Artic Ice - fits in well with a meridional jet - as has been explained on many occasions, a meridional jet pattern warms Polar regions, even as it cools the hemisphere in general."


We have had meridional patterns many times before though. How does that fit in with the general trend of less and less sea-ice through time?


I would suggest very anomalously low-ice years are a combined result of hyper-meridionality AND GHG-related warming. Given that, in turn, less ice may encourage more meridionality, we also appear to have an identifiable example of a positive feedback effect at work.


Cheers - John


Originally Posted by: Maunder Minimum 


I find it hard to understand how GHG related warming could be responsible for loss of Artic sea ice at this juncture - it is simply too early for such an effect to become apparent. There must be other explanations for low sea ice. We had a 30 year spell of positive PDO and regular El Ninos to deal with and therein lies some of the reason for the current situation. I expect the loss of sea ice to reverse in coming years as a consequence of the PDO going negative and other natural cyclic changes in the global climate. It is facile to put current low levels of Artic sea ice down to GHG - during the MWP, there is evidence that Artic conditions were far more benign than subsequently - when the Vikings called Greenland by its name in the 10th century, it wasn't simply for a joke.


Originally Posted by: John Mason 

Another Bulls Eye


This is another area where we've been before and discussed with some considerable passion. What goes round comes round and it would be great to view those old posts again.


The warmists put it down to a regional happening but that would imply that an area was abnormally and anomalously warm for several hundred years without substantial NH atmospheric mixing.


Most unlikely IMO.

"The professional standards of science must impose a framework of discipline and at the same time encourage rebellion against it". – Michael Polyani (1962)
"If climate science is sound and accurate, then it should be able to respond effectively to all the points raised…." - Grandad
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts". - Bertrand Russell
"Science is the belief in the ignorance of the experts" – Richard Feynman
"A consensus means that everyone agrees to say collectively what no one believes individually.”- Abba Eban, Israeli diplomat
Dave,Derby
Maunder Minimum
13 January 2011 14:25:55




Happy new year, all!


"As for loss of Artic Ice - fits in well with a meridional jet - as has been explained on many occasions, a meridional jet pattern warms Polar regions, even as it cools the hemisphere in general."


We have had meridional patterns many times before though. How does that fit in with the general trend of less and less sea-ice through time?


I would suggest very anomalously low-ice years are a combined result of hyper-meridionality AND GHG-related warming. Given that, in turn, less ice may encourage more meridionality, we also appear to have an identifiable example of a positive feedback effect at work.


Cheers - John


Originally Posted by: John Mason 


I find it hard to understand how GHG related warming could be responsible for loss of Artic sea ice at this juncture - it is simply too early for such an effect to become apparent. There must be other explanations for low sea ice. We had a 30 year spell of positive PDO and regular El Ninos to deal with and therein lies some of the reason for the current situation. I expect the loss of sea ice to reverse in coming years as a consequence of the PDO going negative and other natural cyclic changes in the global climate. It is facile to put current low levels of Artic sea ice down to GHG - during the MWP, there is evidence that Artic conditions were far more benign than subsequently - when the Vikings called Greenland by its name in the 10th century, it wasn't simply for a joke.


Originally Posted by: Maunder Minimum 


 


Why too early?


CO2 concentrations have been higher than in the Interglacial maxes for decades!


Cheers - John


Originally Posted by: John Mason 


We are in danger of talking in circles, since all of this has been discussed above - there is simply not enough energy in DLR from increased CO2 to affect ocean temperature in a matter of decades.


Don't know whether this paper has been posted before, but it demonstrates a correlation between cosmic rays, earth albedo and glacial/inter-glacial periodicity:


http://www.gemarsh.com/wp-content/uploads/Interglacials-and-CO2-V2.pdf


 


http://www.gemarsh.com/wp-content/uploads/Interglacials-and-CO2-V2.pdf

New world order coming.
Gray-Wolf
13 January 2011 18:10:02

http://svs.gsfc.nasa.gov/vis/a000000/a003600/a003674/index.html


Now when I run the above not only do I see the '30's warming' in perspective but also where we sit today. Not a pretty colour for the Arctic eh?

Koyaanisqatsi
ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
VIRESCIT VULNERE VIRTUS
nouska
14 January 2011 10:30:50
Anybody have an opinion on this article in the Daily Mail.

http://www.dailymail.co.uk/sciencetech/article-1346936/The-sun-rises-days-early-Greenland-sparking-fears-global-warming-accelerating.html?ito=feeds-newsxml 

My brain goes into paralysis at the mention of equations so have no idea what reduction in horizon height would show sunrise 48 hours earlier. Can someone offer a figure plz or put forward another theory?
polarwind
14 January 2011 11:39:24
http://www.dailymail.co.uk/sciencetech/article-1346936/The-sun-rises-days-early-Greenland-sparking-fears-global-warming-accelerating.html?ito=feeds-newsxml " href="http://www.dailymail.co.uk/sciencetech/article-1346936/The-sun-rises-days-early-Greenland-sparking-fears-global-warming-accelerating.html?ito=feeds-newsxml">http://www.dailymail.co.uk/sciencetech/article-1346936/The-sun-rises-days-early-Greenland-sparking-fears-global-warming-accelerating.html?ito=feeds-newsxml

My brain goes into paralysis at the mention of equations so have no idea what reduction in horizon height would show sunrise 48 hours earlier. Can someone offer a figure plz or put forward another theory?


Hi nouska,


I see the Daily Mail reporting is really topclass -

A report by the World Meteorology Organisation shows that temperatures in Greenland have risen to around 3C (37F) above average over the last year.


Yes, I agree that the lowering of the horizon is the explanation.

However, I would have thought that rather than a lowering of the ice through melting, the better explanation would be reduced snow cover. Although both would have happened. The normal winter accunulation of snow in this area would perhaps be very high. Much depends on the distance from the settlement to the hill that is the horizon. The nearer the better for lack of snow to be the reason. The further away, less importance can be attributed to loss of height. If we are talking 15 metres or so, then snow on the nearer horizon rather than melted ice of 15m or so on either the shorter or long distance horizon, is more likely the principal reason. The loss of 15m of ice in one or two seasons seems too much to me. But I'm prepared to be corrected.


And remember the synoptics have been much different in the very recent past than previously.


Edit: Reduced snow cover would include the melted snow cover of perhaps several seasons where compacted snow rather than ice would have been lost

"The professional standards of science must impose a framework of discipline and at the same time encourage rebellion against it". – Michael Polyani (1962)
"If climate science is sound and accurate, then it should be able to respond effectively to all the points raised…." - Grandad
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts". - Bertrand Russell
"Science is the belief in the ignorance of the experts" – Richard Feynman
"A consensus means that everyone agrees to say collectively what no one believes individually.”- Abba Eban, Israeli diplomat
Dave,Derby
speckledjim
14 January 2011 20:37:40

Temps still very much above average north of 80 degrees


Thorner, West Yorkshire


Journalism is organised gossip
Stephen Wilde
14 January 2011 20:54:31

Yes, the synoptics are pumping cold into North America and Asia whilst Europe sees a respite.

However it is still well below freezing up there and such energy as is flowing into the Arctic is being pumped straight out to space.

Typical of a global cooling scenario which I expect to consolidate during 2011.

To get back to a warming scenario we really need to see a more positive AO closing off the Arctic to warm inflows of air.

Not likely as long as the sun stays quiet and PDO stays negative.

The global tropospheric warmth of recent years is just a lull before a 'storm' and is merely the residual energy from past warming of the oceans in the process of passing through the troposphere on the way to space.

If we do not see significant tropospheric cooling during 2011 then you would not need to announce that I am wrong. I would freely admit it.

Mind you that seems to be a safe position for me to take given the temperature drops of the past 6 months in various key locations as alluded to by Joe ******i and others.

A sudden tropospheric warming with a quiet sun and a strong La Nina would be quite a stretch.
Gray-Wolf
14 January 2011 21:12:15

Another nail in the coffin of "it's all happened before....'' thinkers?


 


http://www.thenewamerican.com/index.php/tech-mainmenu-30/environment/5899-greenland-endures-two-extra-days-of-sunlight


Edit; Ooopsie ,wrong link! Here's the one


http://www.cbc.ca/canada/north/story/2010/12/27/north-high-arctic-24-hour-dark-light-climate-change.html


Had the warming in the 30's been anything like todays we would not have 74yr old Inuit elders being taken aback by the sight (their 'culture' would have a 'race memory' of such events as 'light' in the middle of winter and early 'spring sunrises').

Koyaanisqatsi
ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
VIRESCIT VULNERE VIRTUS
AIMSIR
14 January 2011 21:34:20


Another nail in the coffin of "it's all happened before....'' thinkers?


 


http://www.thenewamerican.com/index.php/tech-mainmenu-30/environment/5899-greenland-endures-two-extra-days-of-sunlight


http://www.dailymail.co.uk/sciencetech/article-1346936/The-sun-rises-days-early-Greenland-sparking-fears-climate-change-accelerating.html


Had the warming in the 30's been anything like todays we would not have 74yr old Inuit elders being taken aback by the sight (their 'culture' would have a 'race memory' of such events as 'light' in the middle of winter and early 'spring sunrises').


Originally Posted by: Gray-Wolf 

Was it a sundog perhaps?.

Gray-Wolf
14 January 2011 22:00:26



Another nail in the coffin of "it's all happened before....'' thinkers?


 


http://www.thenewamerican.com/index.php/tech-mainmenu-30/environment/5899-greenland-endures-two-extra-days-of-sunlight


http://www.dailymail.co.uk/sciencetech/article-1346936/The-sun-rises-days-early-Greenland-sparking-fears-climate-change-accelerating.html


Had the warming in the 30's been anything like todays we would not have 74yr old Inuit elders being taken aback by the sight (their 'culture' would have a 'race memory' of such events as 'light' in the middle of winter and early 'spring sunrises').


Originally Posted by: AIMSIR 

Was it a sun-dog perhaps?.


Originally Posted by: Gray-Wolf 


A plain mirage methinks?


Of all places QI clued me in on this one!!!


When the sun sets apparently it's light is bent by the atmosphere so much that as we see the first bit touch the horizon in reality it has just set!!! so 'normally' the light bends about the size of the Sun's disc. With -5c temps in Llulissat instead of -31c the 'optic's' up there are bound to be a little 'extreme' allowing 'first glimpse' to be seen much earlier than is the norm!!!.


So 'extreme' are the current temp profiles that even the local Inuit have no 'race memory' of such happening before!


 

Koyaanisqatsi
ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
VIRESCIT VULNERE VIRTUS
AIMSIR
14 January 2011 22:33:56




Another nail in the coffin of "it's all happened before....'' thinkers?


 


http://www.thenewamerican.com/index.php/tech-mainmenu-30/environment/5899-greenland-endures-two-extra-days-of-sunlight


http://www.dailymail.co.uk/sciencetech/article-1346936/The-sun-rises-days-early-Greenland-sparking-fears-climate-change-accelerating.html


Had the warming in the 30's been anything like todays we would not have 74yr old Inuit elders being taken aback by the sight (their 'culture' would have a 'race memory' of such events as 'light' in the middle of winter and early 'spring sunrises').


Originally Posted by: Gray-Wolf 

Was it a sun-dog perhaps?.


Originally Posted by: AIMSIR 


A plain mirage methinks?


Of all places QI clued me in on this one!!!


When the sun sets apparently it's light is bent by the atmosphere so much that as we see the first bit touch the horizon in reality it has just set!!! so 'normally' the light bends about the size of the Sun's disc. With -5c temps in Llulissat instead of -31c the 'optic's' up there are bound to be a little 'extreme' allowing 'first glimpse' to be seen much earlier than is the norm!!!.


So 'extreme' are the current temp profiles that even the local Inuit have no 'race memory' of such happening before!


 


Originally Posted by: Gray-Wolf 

I think the optics could be the same as long as the temps are low enough for ice crystals to form in the atomosphere..


It has been an unusually very warm season in that whole area this year.Weird.


There has been massive ice melt on the lower slopes opening them up for mining.Will it last and continue is still a question.


Looks like it might at the moment.I think a lot might depend on the feedback senarios.(not necessarily always severe btw)

Gray-Wolf
15 January 2011 18:02:57

'Sun Day' is a very important time in many countries impacted by 24hr darkness (school kids get a day off for the day etc.) so any deviation to the 'norm' is very freakish and very noticeable to all folk in these areas. Were it not for the Inuit reports from N Greenland of the 'light' conditions in late Dec. we might have been struggling to find an answer to the riddle (try out some of the 'conspiracy sites to see what they are making of it!!!LOL)


Of course the 'local tribes' have very long oral traditions and none speak of such events (across many generations!) so why 'now'???


To me it speaks volumes of the scale of 'changes' we are now living through and events like this 'highlight' just how 'novel' our times are.

Koyaanisqatsi
ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
VIRESCIT VULNERE VIRTUS
Gandalf The White
15 January 2011 20:17:29



Mind you that seems to be a safe position for me to take given the temperature drops of the past 6 months in various key locations as alluded to by Joe ******i and others.

Originally Posted by: Stephen Wilde 


But that is just the worst kind of cherry-picking, as well you know.


The global temperature record is the one to watch, not a few carefully chosen locations.


As we have agreed, if and when the global temperatures show a sustained downward trend then you might have a case. Whether any downward trend will reverse the last decades of warming is even more doubtful.


 

Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


Stephen Wilde
15 January 2011 23:49:18

The point of certain 'key' locations is that whether warming or cooling any trend begins in those locations.

Such locations are those most affected by changes in the meridionality/zonality of the jets. Western Europe is one such location.

Gandalf The White
16 January 2011 12:37:02


The point of certain 'key' locations is that whether warming or cooling any trend begins in those locations.

Such locations are those most affected by changes in the meridionality/zonality of the jets. Western Europe is one such location.

Originally Posted by: Stephen Wilde 


And this is relevant to global temperatures?


This is the Arctic sea ice thread so this is all somewhat irrelevant.


The current sea ice extent figure shows we are still at a record date low but about to come into line with 2006, where there was a marked fall into ice extent for a few days around 20th.

Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


polarwind
16 January 2011 15:24:07



The point of certain 'key' locations is that whether warming or cooling any trend begins in those locations.

Such locations are those most affected by changes in the meridionality/zonality of the jets. Western Europe is one such location.

Originally Posted by: Gandalf The White 


And this is relevant to global temperatures?


This is the Arctic sea ice thread so this is all somewhat irrelevant.


The current sea ice extent figure shows we are still at a record date low but about to come into line with 2006, where there was a marked fall into ice extent for a few days around 20th.


Originally Posted by: Stephen Wilde 

These regions and the flow of the jet, certainly are relevant to global temperatures. And the regional aspect was recognised by climate scientists sometime ago when they acknowledged that the southern continents had little effect. The Arctic Ice thread has also been used as a proxy in the AGW debate, in fact, by itself, it serves little purpose without being within some wider context and it is global warming that is this context.

"The professional standards of science must impose a framework of discipline and at the same time encourage rebellion against it". – Michael Polyani (1962)
"If climate science is sound and accurate, then it should be able to respond effectively to all the points raised…." - Grandad
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts". - Bertrand Russell
"Science is the belief in the ignorance of the experts" – Richard Feynman
"A consensus means that everyone agrees to say collectively what no one believes individually.”- Abba Eban, Israeli diplomat
Dave,Derby
Maunder Minimum
16 January 2011 15:31:15




Mind you that seems to be a safe position for me to take given the temperature drops of the past 6 months in various key locations as alluded to by Joe ******i and others.

Originally Posted by: Gandalf The White 


But that is just the worst kind of cherry-picking, as well you know.


The global temperature record is the one to watch, not a few carefully chosen locations.


As we have agreed, if and when the global temperatures show a sustained downward trend then you might have a case. Whether any downward trend will reverse the last decades of warming is even more doubtful.


 


Originally Posted by: Stephen Wilde 


You appear to be guilty of pre-judging the outcome there Gandalf - let's just see what happens over the next twenty years shall we?


Personally, I remain unconvinced by the more alarmist predictions of AGW, whilst I have no doubt there is a core of scientific truth at its heart. CO2 is a greenhouse gas and increasing its concentrations in the atmosphere will have an effect. However, the effect is logarithmic in its increase, so concentrations have to increase enormously compared to any effects. Also, effects on ocean temperatures, which is key for the global climate, are too small for all the reasons given above, to be currently affecting Artic Sea Ice - we have to look at other inputs to understand what is happening to the Artic.


By all means, we must be more energy efficient, eco-aware and understand that we live in a fragile biosphere - but I would like the main short term attention to concentrate on the loss of biodiversity we are causing, rather than AGW in isolation.


First priority - Stop the destruction of the rain forests!


Second priority - international resolve and action to protect fish stocks!


 

New world order coming.
David M Porter
16 January 2011 15:46:01





Mind you that seems to be a safe position for me to take given the temperature drops of the past 6 months in various key locations as alluded to by Joe ******i and others.

Originally Posted by: Maunder Minimum 


But that is just the worst kind of cherry-picking, as well you know.


The global temperature record is the one to watch, not a few carefully chosen locations.


As we have agreed, if and when the global temperatures show a sustained downward trend then you might have a case. Whether any downward trend will reverse the last decades of warming is even more doubtful.


 


Originally Posted by: Gandalf The White 


You appear to be guilty of pre-judging the outcome there Gandalf - let's just see what happens over the next twenty years shall we?


Personally, I remain unconvinced by the more alarmist predictions of AGW, whilst I have no doubt there is a core of scientific truth at its heart. CO2 is a greenhouse gas and increasing its concentrations in the atmosphere will have an effect. However, the effect is logarithmic in its increase, so concentrations have to increase enormously compared to any effects. Also, effects on ocean temperatures, which is key for the global climate, are too small for all the reasons given above, to be currently affecting Artic Sea Ice - we have to look at other inputs to understand what is happening to the Artic.


By all means, we must be more energy efficient, eco-aware and understand that we live in a fragile biosphere - but I would like the main short term attention to concentrate on the loss of biodiversity we are causing, rather than AGW in isolation.


First priority - Stop the destruction of the rain forests!


Second priority - international resolve and action to protect fish stocks!


 


Originally Posted by: Stephen Wilde 


Well said Maunder- agree 100%.

Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
TomC
  • TomC
  • Advanced Member
16 January 2011 16:58:03


Personally, I remain unconvinced by the more alarmist predictions of AGW, whilst I have no doubt there is a core of scientific truth at its heart. CO2 is a greenhouse gas and increasing its concentrations in the atmosphere will have an effect. However, the effect is logarithmic in its increase, so concentrations have to increase enormously compared to any effects. Also, effects on ocean temperatures, which is key for the global climate, are too small for all the reasons given above, to be currently affecting Artic Sea Ice - we have to look at other inputs to understand what is happening to the Artic.


Originally Posted by: Maunder Minimum 


In answer to your points about the science then doubling CO2 produces 1C warming without feedbacks


The current forcing due to man-made greenhouse gases is around 2 watts / m2 enough to explain the 30 year downward trend of arctic sea -ice over the last 30 years.

polarwind
16 January 2011 18:16:59



Personally, I remain unconvinced by the more alarmist predictions of AGW, whilst I have no doubt there is a core of scientific truth at its heart. CO2 is a greenhouse gas and increasing its concentrations in the atmosphere will have an effect. However, the effect is logarithmic in its increase, so concentrations have to increase enormously compared to any effects. Also, effects on ocean temperatures, which is key for the global climate, are too small for all the reasons given above, to be currently affecting Artic Sea Ice - we have to look at other inputs to understand what is happening to the Artic.


Originally Posted by: TomC 


In answer to your points about the science then doubling CO2 produces 1C warming without feedbacks


The current forcing due to man-made greenhouse gases is around 2 watts / m2 enough to explain the 30 year downward trend of arctic sea -ice over the last 30 years.


Originally Posted by: Maunder Minimum 

For comparison, in this 1995 paper, here the research points to a 3+ watts / m2 change in TSI from 1610 up until 1995? and down to solar cycles activity changes.  I have no idea how well this research stands up. Perhaps someone can get me upto date as to why a smaller figure is adopted based on recent measurements.


We have no direct measurements of TSI back then of course, when the sun was clearly much less active, just proxies. And I accept some proxies are decidedly dodgy.


But such a figure, if taken as correct, would make a big dint in GCM forecasts.

"The professional standards of science must impose a framework of discipline and at the same time encourage rebellion against it". – Michael Polyani (1962)
"If climate science is sound and accurate, then it should be able to respond effectively to all the points raised…." - Grandad
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts". - Bertrand Russell
"Science is the belief in the ignorance of the experts" – Richard Feynman
"A consensus means that everyone agrees to say collectively what no one believes individually.”- Abba Eban, Israeli diplomat
Dave,Derby
Gandalf The White
16 January 2011 18:26:45



 


First priority - Stop the destruction of the rain forests!


Second priority - international resolve and action to protect fish stocks!


 


Originally Posted by: David M Porter 


Well said Maunder- agree 100%.


Originally Posted by: Maunder Minimum 


Iwould agree with both of MM's points - and then some: the list of ecological problems extends quite a long way (coral reefs, species extinction, loss of fresh water - both rivers and underground reserves etc).


Perhaps for another thread - but if we captured land-based animals and birds in the way we trawl the oceans there would be uproar.

Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


TomC
  • TomC
  • Advanced Member
16 January 2011 20:15:18




Personally, I remain unconvinced by the more alarmist predictions of AGW, whilst I have no doubt there is a core of scientific truth at its heart. CO2 is a greenhouse gas and increasing its concentrations in the atmosphere will have an effect. However, the effect is logarithmic in its increase, so concentrations have to increase enormously compared to any effects. Also, effects on ocean temperatures, which is key for the global climate, are too small for all the reasons given above, to be currently affecting Artic Sea Ice - we have to look at other inputs to understand what is happening to the Artic.


Originally Posted by: polarwind 


In answer to your points about the science then doubling CO2 produces 1C warming without feedbacks


The current forcing due to man-made greenhouse gases is around 2 watts / m2 enough to explain the 30 year downward trend of arctic sea -ice over the last 30 years.


Originally Posted by: TomC 

For comparison, in this 1995 paper, here the research points to a 3+ watts / m2 change in TSI from 1610 up until 1995? and down to solar cycles activity changes.  I have no idea how well this research stands up. Perhaps someone can get me upto date as to why a smaller figure is adopted based on recent measurements.


We have no direct measurements of TSI back then of course, when the sun was clearly much less active, just proxies. And I accept some proxies are decidedly dodgy.


But such a figure, if taken as correct, would make a big dint in GCM forecasts.


Originally Posted by: Maunder Minimum 


This is the figure used in papers such as Shindell et al using GCMs to look at the little ice age and comes from Lean et al. Remember that 3 Wm-2 is the change solar flux at the earths orbit (TSI) and the earth is  a sphere. The greenhouse gas forcing refers to the Earth's surface.

polarwind
17 January 2011 21:45:53





Personally, I remain unconvinced by the more alarmist predictions of AGW, whilst I have no doubt there is a core of scientific truth at its heart. CO2 is a greenhouse gas and increasing its concentrations in the atmosphere will have an effect. However, the effect is logarithmic in its increase, so concentrations have to increase enormously compared to any effects. Also, effects on ocean temperatures, which is key for the global climate, are too small for all the reasons given above, to be currently affecting Artic Sea Ice - we have to look at other inputs to understand what is happening to the Artic.


Originally Posted by: TomC 


In answer to your points about the science then doubling CO2 produces 1C warming without feedbacks


The current forcing due to man-made greenhouse gases is around 2 watts / m2 enough to explain the 30 year downward trend of arctic sea -ice over the last 30 years.


Originally Posted by: polarwind 

For comparison, in this 1995 paper, here the research points to a 3+ watts / m2 change in TSI from 1610 up until 1995? and down to solar cycles activity changes.  I have no idea how well this research stands up. Perhaps someone can get me upto date as to why a smaller figure is adopted based on recent measurements.


We have no direct measurements of TSI back then of course, when the sun was clearly much less active, just proxies. And I accept some proxies are decidedly dodgy.


But such a figure, if taken as correct, would make a big dint in GCM forecasts.


Originally Posted by: TomC 


This is the figure used in papers such as Shindell et al using GCMs to look at the little ice age and comes from Lean et al. Remember that 3 Wm-2 is the change solar flux at the earths orbit (TSI) and the earth is  a sphere. The greenhouse gas forcing refers to the Earth's surface.


Originally Posted by: Maunder Minimum 

Can you please explain a little further what you are saying here TomC? I want to get this right.

"The professional standards of science must impose a framework of discipline and at the same time encourage rebellion against it". – Michael Polyani (1962)
"If climate science is sound and accurate, then it should be able to respond effectively to all the points raised…." - Grandad
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts". - Bertrand Russell
"Science is the belief in the ignorance of the experts" – Richard Feynman
"A consensus means that everyone agrees to say collectively what no one believes individually.”- Abba Eban, Israeli diplomat
Dave,Derby

Remove ads from site

Ads